Wireless communication services develop rapidly and user number of various wireless networks continuously increases nowadays. However, a main challenge for the wireless services still is whether the wireless services are able to provide high rate and high performance services. People expect mitigating air multi-path interferences with Orthogonal Frequency Division Multiplexing (OFDM) technology and improving capacity of wireless cells with Multiple Input Multiple Output (MIMO) technology, thus how to improve overall data throughput and edge data throughput of the wireless cells on basis of guaranteeing quality of service (QoS) becomes an important index for scaling QoS of the wireless cells. Because MIMO may achieve high data throughput, IMT-2000 (International Mobile Telecommunications-2000) standard in the 3rd Generation Partnership Project (3GPP) has considered adopting MIMO technology. In the 3rd mobile communication technologies, a base station (BS) makes use of channel state information (CSI) fed back from a user equipment (UE) and changes data transmission rate of transmitter of the base station by adaptive modulation-coding technology. At present, in Super third generation (S3G) cellular mobile communication system, IEEE 802.16 system and WiMAX wireless metropolitan area network system defined by the Long Term Evolution (“LTE”) Committee, it is proposed that the base station uses feedback information (FBI) from the user equipment to optimally design the transmitter so as to highly improve spectrum utilization efficiency. Accordingly, many companies propose feedback information based closed-loop transmission methods which allow the base station to adopt channel quality indicator (CQI) fed back from the user equipment to improve the system performance. Nevertheless, every company has different ideas and schemes on how each user equipment feeds back the CQI information and many companies propose their own CQI feedback schemes such as Bitmap feedback scheme, Best CQI (Best M/Top M) based feedback scheme, Hybrid feedback scheme, Threshold based feedback scheme, etc. After comparing implementation complexity of different feedback schemes with each other and taking into account that superior information feedback scheme is capable of reducing air overhead of feedback information without deteriorating or slightly impairing closed-loop system performance, it is concluded that the best CQI feedback scheme proposed by Motorola Inc. and the Threshold based feedback scheme proposed by Nokia Corporation (Finland) have advantages that principle is simple and it is easy to be carried out, so theses two schemes are possible to be widely applied in the near future. However, so far proposals and relative propositions on “how to decide number of feedback resource blocks in best CQI feedback scheme or Threshold based feedback scheme” have not been brought forward.
Motorola Inc. (USA) released Document R1-070779 “CQI Feedback Scheme for E-UTRA” during 3GPP TSG RAN Meeting No. 48 on Apr. 12-16, 2007 in St. Louis, USA. This document mentions a best feedback number based feedback scheme in which each time the user equipment feeds back CQI information, it selects best M CQIs of resources blocks for feeding back these CQIs to the base station. However, this document does not mention how to determine the number of M.
Nokia Corporation (Finland) released Document R1-070388 “Reduced CQI Design for DL SU-MIMO” during 3GPP TSG RAN Meeting No. 47 on Jan. 15-19, 2007 in Sorrento, Italy. This document mentions a Threshold based feedback scheme in which each time the user equipment feeds back CQI information, it sets CQI threshold value and selects M CQIs of resources blocks which are higher than the threshold value. However, this document does not point out whether the number M is determined by the based station or the user equipment.
In view of these problems, there is need for a high efficient, simple and practical method for deciding the number of feedback resource blocks, which may improve the overall performance of the wireless cell and save spectrum resources of uplinks on the basis of saving signaling overhead at the base station side and reducing the user equipment complexity.